[gnome-contacts] README: Remove Flathub reference

[Niels De Graef <nielsdg src gnome org>]

commit f68eed2adff60711c5323834dca675024eebefcf
Author: Niels De Graef <nielsdegraef gmail com>
Date:   Mon Nov 30 18:14:20 2020 +0100

    README: Remove Flathub reference
    
    The Flatpak build has several issues when there is a version mismatch
    between the build E-D-S and the host E-D-S, so we have a recurrent wave
    of people saying Contacts is broken everytime we release a new version.
    
    I'm not sure what to do with the flatpak build yet, but let's not
    advertise it in our README.

 README.md | 2 --
 1 file changed, 2 deletions(-)
---
diff --git a/README.md b/README.md
index d7fe8539..ac6fa3de 100644
--- a/README.md
+++ b/README.md
@@ -3,8 +3,6 @@
 Contacts organizes your contacts information from all your online and offline
 sources, providing a centralized place for managing your contacts.
 
-[![Flatpak](https://upload.wikimedia.org/wikipedia/commons/thumb/a/a6/Flathub-badge-en.svg/240px-Flathub-badge-en.svg.png)](https://flathub.org/apps/details/org.gnome.Contacts)
-
 ## Building
 
 You can build and install Contacts using [Meson](http://mesonbuild.com/):